Abstract
Purpose :
The Eye Bank Association of America recently reported an increasing incidence of Candida fungal endophthalmitis after corneal transplantation. Corneal storage media in the United States, Optisol-GS, contains antibacterial but no antifungal supplementation. We tested the hypothesis that Optisol-GS supplemented with Amphotericin B or Fluconazole could safely reduce Candida species contamination of corneal transplant media.
Methods :
Candida albicans was grown using Yeast Mold (YM) Agar at 35 degrees Celsius. Next, 12 media vials were prepared, with 8 vials containing diluted inoculum and Optisol-GS supplemented with Amphotericin B or Fluconazole at 0.25x, 0.5x, 1x or 10x MIC. One growth control for each drug was prepared with diluted inoculum, Optisol-GS and sterile water. One sterile control was created for each drug using Optisol-GS and sterile water only. The vials were stored at 35 degrees Celsius in order to promote fungal growth. Cultures were obtained from each vial at 2, 5, 7, and 10 days after inoculation. Safety studies were performed using three mated pairs of human research corneas 1-3 days post-mortem. One cornea from each pair was placed in Optisol-GS containing Fluconazole at the MIC and the other was placed in Optisol-GS alone. The Konan KSS EB10 specular microscope was used for imaging. Endothelial cell counts and morphology were analyzed by a blinded technician at 2, 4, and 6 days post-preservation.
Results :
Amphotericin B did not effectively inhibit fungal growth when stored at 35 degrees Celsius. Optisol- GS supplemented with Fluconazole inhibited Candida albicans growth. The results were analyzed with a One-Way Anova at each time point between the control and 0.25x the MIC (P<0.001). There was no statistically significant decline in endothelial cell count between each cornea stored in Fluconazole supplemented media and their mated controls.
Conclusions :
Though corneas stored in Optisol-GS are standardly refrigerated, warmer temperatures are required for corneal analysis and graft preparation for DMEK and DSAEK. Warming tissue could be a source of fungal growth. In this experiment, a low concentration of Fluconazole inhibited Candida albicans growth at 35 degrees Celsius with no graft toxicity. We conclude that Fluconazole, or the broader-spectrum Voriconazole, could be a stable, safe, and effective addition to Optisol-GS for the prevention of fungal endophthalmitis.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.